


World So Cold

by WolfKomoki



Category: Arrow (TV 2012), The Flash (TV 2014)
Genre: Alternate Universe, Gen, Role Reversal
Language: English
Status: In-Progress
Published: 2017-04-22
Updated: 2017-08-26
Packaged: 2018-10-22 10:17:30
Rating: Mature
Warnings: Major Character Death
Chapters: 3
Words: 3,073
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10694973
Author URL: https://archiveofourown.org/users/WolfKomoki/pseuds/WolfKomoki
Summary: When Henry is killed by Zoom, Caitlin runs back in time to the day that Nora Allen was murdered, and she saves her. Caitlin lets Barry be happy for a while, until she starts to forget her old life. Caitlin didn't want to forget her old life, so she goes back to that day, and lets Eobard kill Barry's mother. Caitlin had tried to fix the timeline, but it turns out that she had broken it. Knowing that she is the one that caused Barry to get his ice powers is a constant reminder that she screwed up.





	1. Chapter 1

**Author's Note:**

> The Flash is owned by The CW. This story was requested by Bookwormliz99 on fanfiction.net. They wanted a story where Barry is Killer Frost instead of Caitlin. So then I got the idea to swap Barry and Caitlin's powers.

          Caitlin loved having super speed. Being able to run at super speed was pure adrenaline and euphoria. She never wanted to stop running. The day that Zoom killed Barry’s father, that became the day that she _needed_ to run, and so she did. She ran back in time to the day that Nora was murdered. When she gets to that day, she runs to Central City, and to Barry’s old house.

          “You’re not going to hurt her ever again.” She growls, and that’s when she runs towards the Reverse Flash, shoving the knife out of his hand as she places power dampening cuffs against his wrists.

          “I don’t understand, who are you?” Nora asks.

          “It’s okay now, you and your son are safe. I’m the Flash, and he’s never going to hurt anyone ever again.” Caitlin tells her. Yes, Caitlin had considered going back to save her father, but Barry was hurting more, and so, she decided to save Barry’s mother instead. When she cuffed The Reverse Flash, Caitlin runs back to the timeline, and places him in an abandoned building with a metahuman cell that she designed herself. When she gets back though, she immediately notices that something was wrong with the timeline.

          For one thing, her mother was dead, and her father was alive. Second, Caitlin was now a doctor that specializes in eye care. Third, Star Labs was now Ramon Industries. Fourth, Cisco Ramon was rich. Fifth, Team Flash no longer exists.

          Sixth, Caitlin is no longer The Flash, Wally West is. Seventh, Joe West is an alcoholic. It was okay though, because Barry was happy, she tells herself. She lets Barry be happy for a while, until she starts forgetting her old life. So, she decides to interrogate Eobard Thawne.

          “I was wondering when you’d start to notice.” He smirks.

          “Notice _what?_ What’s happening to me? Why am I forgetting?” Caitlin demands, and that’s when he starts laughing.

          “What? What the hell is so funny?” Caitlin growls.

          “Your speed!” He continues laughing.

          “What _about_ my speed?” Caitlin snaps.

          “You were never meant to be the Flash in this timeline. The more you use your powers, the more you forget about your old life.” Eobard finally explains.

          “How do I stop it?” Caitlin asks.

          “Now darling, that’s up to you to figure out.” Eobard laughs. Caitlin growls in frustration as she slides the food in his cell. It was about a week later when she figures it out. _If I want to fix the timeline, then I have to let Barry’s mother die._

          “Oh Barry, I’m so sorry.” She apologizes, and that’s when she returns to Eobard’s cell.

          “I need you to do it.” She sighs, staring at the floor.

          “Do what?” Eobard asks.

          “You know what.” Caitlin growls.

          “Yes, but I need to hear you say it.” Eobard smirks.

          “I need you to kill Barry’s mother.” Caitlin sighs.

          “Of course, dear.” Eobard smirks, and that’s when she and Eobard ran back to that day. Caitlin cried when she gets there. She had granted Barry happiness, and now she was taking that away from him for selfish reasons. Caitlin couldn’t bear to watch him do it, so she stood outside the door, waiting for him to finish the job. It was when blade hit flesh that Caitlin knew that the job was done, and the guilt set in.

          Once the job was done, she returned to the timeline, sighing with relief when she returns to Star Labs, instead of Ramon Industries. So far, everything seemed okay. Slowly, she returns to the main room of Star Labs as she takes in her surroundings. Cisco, Joe, HR, Wally, and Iris were there, but Caitlin couldn’t see Barry anywhere.

          “Where’s Barry?” Caitlin asks.

          “Okay, I’m going to blame that one on lack of sleep.” Joe growls.

          “What do you mean?” Caitlin asks with confusion.

          “Caitlin, you know that Barry quit the team after Henry’s death.” Cisco reminds her.

          “Where is he?” Caitlin asks.

          “I don’t know. The last I heard he had gotten an apartment in Star City. After that, he stopped speaking to us.” Iris sighs.

          Barry had returned to Central City for the first time in a long time. After they had locked him up in a cell instead of comforting him in his grief, Barry refused to be a member of Team Flash ever again. It was nice working with Team Arrow, as they had comforted him in his grief. They still cared about him. Today he had an appointment with Carla Tannhauser. It was Barry’s hope that she could help get rid of his ice powers, before he becomes like his Earth-2 doppelganger: Killer Frost.

          Slowly, he walks up to the front desk of Tannhauser Industries.

          “Can I help you?” The woman at the front desk asks.

          “I'm here to see Dr. Tannhauser.” Barry informs.

          “Do you have an appointment?” The woman asks.

          “It’s alright Jackie, this is the man I told you about Barry Allen.” Carla informs, walking over to her.

          “So, Mr. Allen. Why did you make this appointment with me?” Carla asks, taking him into her office.

          “I read your new paper on applications in cryo-medicine, and I think you might be able to help.” Barry informs.

          “Help who Mr. Allen?” Carla asks.

          “Please, call me Barry.” Barry pleads.

          “Alright, Barry. Who needs my help?” Carla asks.

          “A friend.” Barry lies

          “Well, if you want to send over the file, I'll be happy to take a look, when I have a chance, but right now, I have a shareholder meeting to prepare for.” Carla tells him.

          “Ms. Tannhauser!” Barry yells, slamming his hands on the table. When he slammed his hands on the table, it froze solid.

          “ _I’m_ the one that needs help!” He screams. It was then that she speaks to Jackie at the front desk.

          “Cancel my appointments, and have Nigel meet me in the bio-lab. We have work to do.” Carla informs, taking Barry to meet Nigel. Slowly, they placed a device on Barry’s arms that would monitor him when he uses his powers.  
  


 

  
  


 

         

 

 

 

 

 


	2. Chapter 2

          “Sorry, cold hands.” Nigel apologizes.

          “I didn’t even notice.” Barry admits.

          “I’m Nigel by the way. Nice to meet you. We’re going to help you figure this out, Barry. Let’s get you to the lab.” Nigel informs, leading him there. It was then that Barry notices a large, orange, glowing tube in the lab.

          “What’s that thing?” He asks.

          “It's to test how your ability affects molecular motion. That shaft is solid tungsten, and it's heated to over 2,000 degrees centigrade.” Carla explains.

          “Okay, but what am I doing with it?” Barry asks.

          “I want you to cool it down, and when we determine how you can do that, we can figure out the best way to help you.” Carla instructs.

          “I wanted to thank you, for doing this. I know this is an usual request.” Barry smiles.

          “You’re stalling. Go on, do it.” Carla chuckles. Slowly, Barry freezes the tube.

          “How long have you had these abilities, if you don’t mind my asking?” Carla wonders.

          “They started manifesting a few months ago, but I'm assuming I got them when the particle accelerator exploded, just like all the other metas.” Barry answers simply.

          “And you haven’t told anyone? Surely you would have told your family about these abilities over a total stranger.” Carla asks.

          “My so-called family locked me in a cell when I was grieving, instead of comforting me in my grief. So, no. I have no family.” Barry growls.

          “I’m sorry to hear that. Surely you must have friends?” Carla asks.

          “My so-called friends were part of the people that locked me up, so nope, no friends either.” Barry growls.

          “You must have someone that cares for you.” Carla sighs.

          “Well, I do have some… coworkers. They seem to care for me.” Barry admits, referring to Team Arrow.

          “Why wouldn’t you tell _them_ about these abilities then?” Carla asks.

          “None of them have abilities, and I was afraid of how they would react.” Barry explains.

          “Ah, so you wanted a stranger who wouldn’t judge you.” Carla realizes.

          “Exactly.” Barry smiles, grateful that she understands.

          “Dr. Tannhauser, look at this.” Nigel calls, pointing to the readings.

          “He’s absorbed all that energy? How?” Carla asks.

          “I'm not sure yet, but if we can figure that out, this could change everything we're doing here.” Nigel smiles.

          “Okay, be still.” Carla orders, grabbing a needle.

          “What are you testing for now?” Barry asks as Nigel tries to find a vein.

          “Any polymorphism that could help us understand how you're able to absorb that much energy from molecules to create gelid surroundings.” Carla explains. _They’re studying me like a lab rat. I don’t like this._ Barry thinks as Nigel takes him to a white room.

          “I don’t like this.” Barry growls, grabbing his book bag as he starts to leave.

          “You’re leaving us?” Nigel asks.

          “Well, you’re treating me like a lab rat, so yeah, I am.” Barry snaps. Suddenly, Nigel locks the door.

          “What are you _doing_?” Barry shrieks.

          “Sorry, Frosty, but you're not going anywhere.” Nigel informs.

          “Let me out of here! Open these doors!” Barry screams.

          “I said no! I am sick of working day after day, night after night, only to have my work benefit her! With the information, I can get from you, I can finally get out of this place, so you're gonna stay here until I get everything that I need.” Nigel snaps.

          “You’re not going to test me like a damn lab rat!” Barry screams.

          “Yes Barry, I _am_.” Nigel growls, grabbing his arm.

          “No, you’re _not_!” Barry growls, his voice echoing, and his eyes glowing a grey color as he freezes Nigel’s arm.

          “Ah, ah! Stop, Stop!” He pleads, groaning in pain. Within seconds, Carla unlocks the door and runs inside.

          “Barry, _stop_! You don’t want to do this!” Carla gasps.

          “You don’t know, a damn _thing_ about me!” Barry coldly snaps.

          “Maybe I don’t, but what I do know is that you’re a good man. You don’t want to hurt anyone!” Carla gasps, trying to get through to him. Slowly, Barry’s eyes turn back to normal and he stops freezing Nigel.

          “I’m so sorry I-you know what, I’ll just go.” Barry apologizes.

          “For whatever it’s worth, I’m here to lend a shoulder, if you need it.” Carla offers.

          “Thank you.” Barry smiles.

          “Now go. I’ll take care of him. I’ll say it was an accident with some of the chemicals, no one will ever have to know.” Carla informs, and that’s when Barry leaves the building. Barry had forgiven them after he left for Star City, but he would never forget how they treated him when he was grieving. He didn’t care anymore though, Barry didn’t let himself feel emotions anymore. Today, he was coming back to Central City.

          It was about an hour later when the cab drops Barry off at the CCPD. Since he joined Team Arrow as Red Sun, Barry has become quite an athlete. So, he decides to walk to Star Labs, carrying his book bag.

Slowly, he walks inside to see Joe, Cisco, Iris, Wally, HR, and Caitlin.

          “Oh, my God Barry!” Iris exclaims, running over to hug Barry.

          “Barry, we’ve been worried _sick_ about you!” Joe snaps.

          “Oh? I didn’t know you _cared_.” Barry scoffs.

          “Of _course,_ we care about you!” Wally shouts.

          “Really? Well, you have a very funny way of showing it after you locked me in a damn _cell!_ ” Barry growls.

          “Come on Barry, I’m _sorry_!” Joe apologizes.

          “Fine, apology accepted. Caitlin, I could use your help.” Barry informs.

          “You could at least say _hello_ Barry, but fine. What do you need?” Caitlin asks.

          “How familiar are you with cryo medicine?” Barry asks.

          “Pretty familiar. Why?” Caitlin asks. It was then that Barry touches one of the monitors, watching as it freezes solid.

          “Holy Shit Barry!” Cisco gasps.

          “Is this why you took off?” Iris asks.

          “No.” Barry answers simply.

          “Then why?” Iris asks.

          “Simply put? I was angry with all of you. So, I moved to Star City to work through my grief.” Barry answers.

          “Are you coming back? We miss you, Barry.” Joe asks.

          “I don’t know.” Barry answers simply.

 

  
  


 

 

  
  


  
  


  
  
  
  


 

 

 

 

 

 

 

 


	3. Chapter 3

          It’s been three days since Barry came back to Star Labs. Wally is stuck in some sort of cocoon, and Joe is becoming frustrated. Barry doesn’t know where Joe is right now, but he doesn’t care. Barry wants to explore these Alchemy rumors that he’s been hearing about since he came back to Central City, and the precinct was the perfect place to do that, so he grabs his laptop bag, and walks there. When he gets there, he finds it empty, and that’s when he knocks out the cameras with his ice.

When he does that, his eyes start glowing, and that’s when he feels his powers take over.

          “Excuse me? Can I help you?” A voice greets, and that’s when Barry looks over to see Julian looking at him.

          “Did you do that to the cameras?” Julian asks, seeing them covered in solid blocks of ice. Barry hits him as hard as he can, catching him as he passes out. Now that he was unconscious, he takes him to an abandoned frozen food warehouse. When he gets there, he puts him in the chair, and lowers the temperature in the room, tying his legs to the chair. Not enough to kill him, but enough to make him uncomfortable. It was about ten minutes later when Julian regained consciousness.

“Finally, I was starting to grow bored waiting for you to wake up.” Barry spoke. His voice was hollow, and it echoed. Julian looks down to see that his legs have been tied to the chair.

          “A bit chilly in here, isn’t it?” Julian complains.

          “Shut up. I need to think.” Barry snaps.

          “Look, I know who you are, okay? You’re… you’re… you’re the former Forensic Scientist, Barry Allen, right? The one that Singh is so fond of?” Julian asks.

          “I said be quiet!” Barry shrieks.

          “Are you going to kill me?” Julian hesitantly asks.

          “I need to find Alchemy.” Barry demands.

          “Alchemy? What? What do you want with him?” Julian asks with confusion.

          “Alchemy has disciples, followers. I need you to create an algorithm that will allow you to locate anyone who has searched for a specific keyword in the last six months. If we find one of his followers, they can take me to Alchemy.” Barry explains.

          “Okay. But "alchemy" is a relatively common phrase. It'll have hundreds of hits.” Julian tells him, looking at the laptop Barry had placed in front of him.

          “Then search for an uncommon one.” Barry growls.

          “Such as?” Julian asks.

          “Savitar.” Barry answers. He’d heard of this Savitar around the same time the Alchemy rumors started spilling, but it wasn’t as popular.

          “Savitar?” Julian asks, making sure he heard that right. Barry makes a blade of ice, and points it towards Julian.

          “ _Get to searching_.” He growls, bringing the blade closer.

          “Alright, alright, alright, just don’t hurt me, please!” Julian panics, entering in the keywords. Meanwhile, at the precinct, Singh and Patterson were having a conversation.

          “Detective Patterson? Hey. What's going on?” Singh asks with concern.

          “Just the man I want to see. Your little friend's in big trouble, Singh.” Patterson states.

          “My friend?” Singh asks with confusion.

          “A male meta-human attacked the precinct, took Julian Albert hostage.” Patterson snaps.

          “Julian? Wait, do you know who the meta is?” Singh asks.

          “Uh, no, but he’s smart, I’ll tell you that. Took out our security cameras so we couldn't ID him. I thought maybe you’d recognize him.” Patterson informs, showing him the footage. When he sees the footage his heart breaks. _Oh Allen, what are you doing kid?_

“No. Why would he take Julian?” Singh lies.

          “He’s a meta. They’re all crazy, but don’t worry, we’ll get him.” Patterson informs, leaving the room.

          “What are you doing? What are you doing Barry?” David sighs.

          “I found two individuals that have searched for the name Savitar. Here are both their addresses, both in Central City. What exactly are you gonna do to them?” Julian hesitantly asks.

          “I don’t know.” Barry answers. Slowly, his eyes return to normal. _What am I doing?_ He thinks, and that’s when Julian sends out a message to the precinct.

          “Son of a! I’m going!” David gasps, having been the first person to find Julian’s location. After getting in the cruiser, he drives to the frozen food warehouse, parking the cruiser out of sight. After that, he slowly walks inside.

          “ _Barry!”_ He shouts, hoping to get his attention.

          “You! You sent out a message, didn’t you?” Barry snaps, grabbing Julian’s arm as he freezes it. Julian cries out in pain, and that’s when David gets closer.  
          “Barry, come on, let him go.” David pleads. David never knew what had happened to Barry, but hearing Barry tell Joe to go to hell as he stormed out of the precinct five months ago broke his heart. He didn’t know what Joe could ever do to deserve such a reaction, but he could tell that whatever it was, Barry was still hurting for it. Barry shot ice at his feet, a warning shot.

          “ _Don’t_ move. You do, I’ll freeze you _both_ to death.” Barry threatens. Barry hears Caitlin shout his name, and that’s when he lets Julian go.

          “ _Go._ Before I change my mind.” Barry growls, and that’s when Julian runs out the back door. David watched as Caitlin raced in the room.

“Go! Get out of here before he hurts you!” David shouts. Before she gets that chance, Barry brings ice to his hands, running over to Caitlin as he puts his hand to her neck, watching as hypothermia sets in.

          “Oh my God! What did you _do_? What did you _do_?” David shouts, running over to Caitlin. Barry’s eyes widened in horror at what he’d done, and that’s when he runs outside the building. Now that Barry was gone, David runs over to Caitlin.

          “I don’t know if you can hear me, but I’ve got to get you into some warmer clothes.” David calls, taking off her jacket and her shirt. After that, he wraps his jacket around her, and that’s when he straps her in the back of the cruiser, turning on the heater as he races to Star Labs.  
  


  
  


  


  
  


 

  
  


  
  


 

 

 

 

 

 

 

 

         

 

**Notes for the Chapter:**

> Question for you guys: Since Barry isn't a speedster in this au, and Caitlin is, who do you want Savitar to be? Your choices are:  
> A time remnant of Caitlin, A time remnant of Wally, or Caitlin's future self, or Wally's future self. You have until Tuesday, August 29th to vote. From there, whichever choice got the most votes will become Savitar.


End file.
